If you are going to use 'entanglement' to teleport quantum information on a practical scale, it needs to be worked out how entanglement could be 'recycled' to increase the efficiency of these connections.

Writing in

*Physical Review Letters* , a group has done just that - mathematically. They have

also devised a generalized form of teleportation, which allows for a wide variety of potential applications in quantum physics.

Long a staple of science-fiction, teleportation became a 'it might work in principle' idea in 1993, when theoretical physicists calculated that teleportation could work mathematically using quantum laws. Quantum teleportation harnesses 'entanglement' to transmit particle-sized bites of information across potentially vast distances in an instant. Entanglement involves a pair of quantum particles such as electrons or protons that are intrinsically bound together, retaining synchronisation between the two that holds whether the particles are next to each other or on opposing sides of a galaxy. Through this connection, quantum bits of information - qubits - can be relayed using only traditional forms of classical communication.

Einstein famously disliked the idea of quantum entanglement, dismissing it ahas since been proven to bet one point as "spooky action at a distance". But entanglement is a very real feature of our universe, and therefore has potential, but resist the clarion call of the "Beam Me Up, Scotty" titles mainstream media will be dishing out this week.

Teleportation hypotheses have fallen into one of two camps, those that could only send scrambled information requiring correction by the receiver and, more recently, "port-based" teleportation that doesn't require a correction, but requires an impractical amount of entanglement and each object sent would destroy the entangled state.

Theoretical physicists from Cambridge, University College London and the University of Gdansk have now developed a new mathematical framework they say could provide an optimal solution in which the entangled state is 'recycled', so that the gateway between particles holds for the teleportation of multiple objects. They have even devised a protocol in which multiple qubits can be teleported simultaneously, although the entangled state degrades proportionally to the amount of qubits sent in both cases.

"The first protocol consists of sequentially teleporting states, and the second teleports them in a bulk," said Sergii Strelchuck from Cambridge's Department of Applied Mathematics and Theoretical Physics. "We have also found a generalised teleportation technique which we hope will find applications in areas such as quantum computation.

"There is a close connection between teleportation and quantum computers, which are devices which exploit quantum mechanics to perform computations which would not be feasible on a classical computer. Building a quantum computer is one of the great challenges of modern physics, and it is hoped that the new teleportation protocol will lead to advances in this area."

This new protocol is completely mathematical but last year a team of Chinese scientists reported teleporting photons over 143km, breaking previous records, and quantum entanglement is continually researched. Teleportation of information carried by single atoms is feasible with current technologies, but the teleportation of large objects - such as Captain Kirk (ta-da! See, we made a "Star Trek" reference too, so thanks for all the attention) remains in the realm of science fiction.

Adds Strelchuck, "Entanglement can be thought of as the fuel, which powers teleportation. Our protocol is more fuel efficient, able to use entanglement thriftily while eliminating the need for error correction."

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